Although applicable to any airframe structures, the present invention and the problem on which it is based are explained in more detail with reference to a landing gear well in an aircraft fuselage.
In order to explain the general problem, FIG. 5 shows, in a perspective view, a section through an aircraft fuselage section 1 which has a landing gear well 2. The landing gear well 2 has essentially two functions:
First of all, the landing gear well 2 serves to accommodate the landing gear 3 during the flight phase. For this purpose, after the aircraft has taken off, the landing gear 3 is retracted from a deployed position into a retracted position, with essential parts of the landing gear 3, in particular the wheels, projecting into the landing gear well 2.
In the event of a difference in pressure between the cabin pressure prevailing in the interior 4 of the aircraft and the atmospheric external pressure prevailing in the interior 7 of the landing gear well 2, considerable loads act on the landing gear well 2. In addition to simply accommodating the landing gear 3, a further function of the landing gear well 2 is consequently to ensure absorption of the loads resulting from the difference in pressure and to guarantee sealing under pressure.
In order to satisfy these two functions, the conventional landing gear well 2 has the following structure which is explained briefly with reference to FIG. 5:
A rear pressure bulkhead 5—the view in FIG. 5 is oriented approximately in the direction of the aircraft nose, a cover surface 9 and a further front pressure bulkhead, not illustrated, form the landing gear well 2 and end in a pressure tight manner with the fuselage shell 6.
The rear pressure bulkhead 5 has a flat, rear pressure plate 12, the latter being reinforced by means of braces 18 . . . 23. The cover surface 9 is provided with membrane components 25 . . . 30 with a single curvature. The curvature of the membrane components 25 . . . 30 improves the force flux, which results from the difference in pressure, in the membrane components 25 . . . 30 in such a manner that bending stresses therein are greatly reduced, and they can therefore be designed to be substantially thinner than the rear pressure plate 12 and therefore to have a lower weight.
The problem therewith is that the front and rear pressure bulkhead 5 contribute substantially to the aircraft weight and therefore reduce the payload of the aircraft.
It is therefore the object of the present invention to provide a lighter landing gear well which, in particular, is suitable for any desired construction spaces and joining requirements.